//--------------------------------------------------------------------------
//	Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
//  All rights reserved.
//
//	Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are
//  met:
//
//	Redistributions of source code must retain the above copyright notice,
//  this list of conditions and the following disclaimer.
//	Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
//	Neither the name of the Drew Davidson nor the names of its contributors
//  may be used to endorse or promote products derived from this software
//  without specific prior written permission.
//
//	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
//  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
//  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
//  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
//  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
//  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
//  DAMAGE.
//--------------------------------------------------------------------------
package com.ishitong.freesql.ognl;


/**
 * JJTree interface for AST nodes, as modified to handle the OGNL operations
 * getValue and setValue. JJTree's original comment: <p/> All AST nodes must
 * implement this interface. It provides basic machinery for constructing the
 * parent and child relationships between nodes.
 * 
 * @author Luke Blanshard (blanshlu@netscape.net)
 * @author Drew Davidson (drew@ognl.org)
 */
public interface Node
{

	/**
	 * This method is called after the node has been made the current node. It
	 * indicates that child nodes can now be added to it.
	 */
	public void jjtOpen();

	/**
	 * This method is called after all the child nodes have been added.
	 */
	public void jjtClose();

	/**
	 * This pair of methods are used to inform the node of its parent.
	 */
	public void jjtSetParent(Node n);

	public Node jjtGetParent();

	/**
	 * This method tells the node to add its argument to the node's list of
	 * children.
	 */
	public void jjtAddChild(Node n, int i);

	/**
	 * This method returns a child node. The children are numbered from zero,
	 * left to right.
	 */
	public Node jjtGetChild(int i);

	/**
	 * Return the number of children the node has.
	 */
	public int jjtGetNumChildren();

	// OGNL additions to Node:

	/**
	 * Extracts the value from the given source object that is appropriate for
	 * this node within the given context.
	 */
	public Object getValue(OgnlContext context, Object source) throws OgnlException;

	/**
	 * Sets the given value in the given target as appropriate for this node
	 * within the given context.
	 */
	public void setValue(OgnlContext context, Object target, Object value) throws OgnlException;
}
